tmpfiles.d

title: tmpfiles.d(5)

text:
# tmpfiles.d(5)

## NAME
tmpfiles.d - Configuration for creation, deletion and cleaning of volatile and temporary files

## SYNOPSIS

```
/etc/tmpfiles.d/*.conf
/run/tmpfiles.d/*.conf
/lib/tmpfiles.d/*.conf

```

```
~/.config/user-tmpfiles.d/*.conf
$XDG_RUNTIME_DIR/user-tmpfiles.d/*.conf
~/.local/share/user-tmpfiles.d/*.conf
...
/usr/share/user-tmpfiles.d/*.conf

```

```
#Type Path                                     Mode User Group Age         Argument
f     /file/to/create                          mode user group -           content
f+    /file/to/create-or-truncate              mode user group -           content
w     /file/to/write-to                        -    -    -     -           content
w+    /file/to/append-to                       -    -    -     -           content
d     /directory/to/create-and-cleanup         mode user group cleanup-age -
D     /directory/to/create-and-remove          mode user group cleanup-age -
e     /directory/to/cleanup                    mode user group cleanup-age -
v     /subvolume-or-directory/to/create        mode user group -           -
q     /subvolume-or-directory/to/create        mode user group -           -
Q     /subvolume-or-directory/to/create        mode user group -           -
p     /fifo/to/create                          mode user group -           -
p+    /fifo/to/[re]create                      mode user group -           -
L     /symlink/to/create                       -    -    -     -           symlink/target/path
L+    /symlink/to/[re]create                   -    -    -     -           symlink/target/path
c     /dev/char-device-to-create               mode user group -           major:minor
c+    /dev/char-device-to-[re]create           mode user group -           major:minor
b     /dev/block-device-to-create              mode user group -           major:minor
b+    /dev/block-device-to-[re]create          mode user group -           major:minor
C     /target/to/create                        -    -    -     -           /source/to/copy
x     /path-or-glob/to/ignore/recursively      -    -    -     -           -
X     /path-or-glob/to/ignore                  -    -    -     -           -
r     /empty/dir/to/remove                     -    -    -     -           -
R     /dir/to/remove/recursively               -    -    -     -           -
z     /path-or-glob/to/adjust/mode             mode user group -           -
Z     /path-or-glob/to/adjust/mode/recursively mode user group -           -
t     /path-or-glob/to/set/xattrs              -    -    -     -           xattrs
T     /path-or-glob/to/set/xattrs/recursively  -    -    -     -           xattrs
h     /path-or-glob/to/set/attrs               -    -    -     -           file attrs
H     /path-or-glob/to/set/attrs/recursively   -    -    -     -           file attrs
a     /path-or-glob/to/set/acls                -    -    -     -           POSIX ACLs
a+    /path-or-glob/to/append/acls             -    -    -     -           POSIX ACLs
A     /path-or-glob/to/set/acls/recursively    -    -    -     -           POSIX ACLs
A+    /path-or-glob/to/append/acls/recursively -    -    -     -           POSIX ACLs
```

## DESCRIPTION
tmpfiles.d configuration files provide a generic mechanism to define the creation of regular files, directories, pipes, and device nodes, adjustments to their access mode, ownership, attributes, quota assignments, and contents, and finally their time-based removal. It is mostly commonly used for volatile and temporary files and directories (such as those located under /run/, /tmp/, /var/tmp/, the API file systems such as /sys/ or /proc/, as well as some other directories below /var/).

systemd-tmpfiles uses this configuration to create volatile files and directories during boot and to do periodic cleanup afterwards. See systemd-tmpfiles(8) for the description of systemd-tmpfiles-setup.service, systemd-tmpfiles-clean.service, and associated units.

System daemons frequently require private runtime directories below /run/ to store communication sockets and similar. For these, it is better to use RuntimeDirectory= in their unit files (see systemd.exec(5) for details), if the flexibility provided by tmpfiles.d is not required. The advantages are that the configuration required by the unit is centralized in one place, and that the lifetime of the directory is tied to the lifetime of the service itself. Similarly, StateDirectory=, CacheDirectory=, LogsDirectory=, and ConfigurationDirectory= should be used to create directories under /var/lib/, /var/cache/, /var/log/, and /etc/. tmpfiles.d should be used for files whose lifetime is independent of any service or requires more complicated configuration.

## CONFIGURATION DIRECTORIES AND PRECEDENCE
Each configuration file shall be named in the style of package.conf or package-part.conf. The second variant should be used when it is desirable to make it easy to override just this part of configuration.

Files in /etc/tmpfiles.d override files with the same name in /lib/tmpfiles.d and /run/tmpfiles.d. Files in /run/tmpfiles.d override files with the same name in /lib/tmpfiles.d. Packages should install their configuration files in /lib/tmpfiles.d. Files in /etc/tmpfiles.d are reserved for the local administrator, who may use this logic to override the configuration files installed by vendor packages. All configuration files are sorted by their filename in lexicographic order, regardless of which of the directories they reside in. If multiple files specify the same path, the entry in the file with the lexicographically earliest name will be applied (note that lines suppressed due to the "!" are filtered before application, meaning that if an early line carries the exclamation mark and is suppressed because of that, a later line matching in path will be applied). All other conflicting entries will be logged as errors. When two lines are prefix path and suffix path of each other, then the prefix line is always created first, the suffix later (and if removal applies to the line, the order is reversed: the suffix is removed first, the prefix later). Lines that take globs are applied after those accepting no globs. If multiple operations shall be applied on the same file (such as ACL, xattr, file attribute adjustments), these are always done in the same fixed order. Except for those cases, the files/directories are processed in the order they are listed.

If the administrator wants to disable a configuration file supplied by the vendor, the recommended way is to place a symlink to /dev/null in /etc/tmpfiles.d/ bearing the same filename.

## CONFIGURATION FILE FORMAT
The configuration format is one line per path, containing type, path, mode, ownership, age, and argument fields. The lines are separated by newlines, the fields by whitespace:

```
#Type Path        Mode User Group Age Argument...
d     /run/user   0755 root root  10d -
L     /tmp/foobar -    -    -     -   /dev/null
```

Fields may contain C-style escapes. With the exception of the seventh field (the "argument") all fields may be enclosed in quotes. Note that any whitespace found in the line after the beginning of the argument field will be considered part of the argument field. To begin the argument field with a whitespace character, use C-style escapes (e.g. "\x20").

### Type
The type consists of a single letter and optionally an exclamation mark ("!") minus sign ("-"), and/or equals sign ("=").

The following line types are understood:

f, f+

f will create a file if it does not exist yet. If the argument parameter is given and the file did not exist yet, it will be written to the file. f+ will create or truncate the file. If the argument parameter is given, it will be written to the file. Does not follow symlinks.

w, w+

Write the argument parameter to a file, if the file exists. If suffixed with +, the line will be appended to the file. If your configuration writes multiple lines to the same file, use w+. Lines of this type accept shell-style globs in place of normal path names. The argument parameter will be written without a trailing newline. C-style backslash escapes are interpreted. Follows symlinks.

d

Create a directory. The mode and ownership will be adjusted if specified. Contents of this directory are subject to time based cleanup if the age argument is specified.

D

Similar to d, but in addition the contents of the directory will be removed when --remove is used.

e

Adjust the mode and ownership of existing directories and remove their contents based on age. Lines of this type accept shell-style globs in place of normal path names. Contents of the directories are subject to time based cleanup if the age argument is specified. If the age argument is "0", contents will be unconditionally deleted every time systemd-tmpfiles --clean is run. For this entry to be useful, at least one of the mode, user, group, or age arguments must be specified, since otherwise this entry has no effect. As an exception, an entry with no effect may be useful when combined with !, see the examples.

v

Create a subvolume if the path does not exist yet, the file system supports subvolumes (btrfs), and the system itself is installed into a subvolume (specifically: the root directory / is itself a subvolume). Otherwise, create a normal directory, in the same way as d. A subvolume created with this line type is not assigned to any higher-level quota group. For that, use q or Q, which allow creating simple quota group hierarchies, see below.

q

Create a subvolume or directory the same as v, but assign the subvolume to the same higher-level quota groups as the parent. This ensures that higher-level limits and accounting applied to the parent subvolume also include the specified subvolume. On non-btrfs file systems, this line type is identical to d. If the subvolume already exists, no change to the quota hierarchy is made, regardless of whether the subvolume is already attached to a quota group or not. Also see Q below. See btrfs-qgroup(8) for details about the btrfs quota group concept.

Q

Create the subvolume or directory the same as v, but assign the new subvolume to a new leaf quota group. Instead of copying the higher-level quota group assignments from the parent as is done with q, the lowest quota group of the parent subvolume is determined that is not the leaf quota group. Then, an "intermediary" quota group is inserted that is one level below this level, and shares the same ID part as the specified subvolume. If no higher-level quota group exists for the parent subvolume, a new quota group at level 255 sharing the same ID as the specified subvolume is inserted instead. This new intermediary quota group is then assigned to the parent subvolume's higher-level quota groups, and the specified subvolume's leaf quota group is assigned to it. Effectively, this has a similar effect as q, however introduces a new higher-level quota group for the specified subvolume that may be used to enforce limits and accounting to the specified subvolume and children subvolume created within it. Thus, by creating subvolumes only via q and Q, a concept of "subtree quotas" is implemented. Each subvolume for which Q is set will get a "subtree" quota group created, and all child subvolumes created within it will be assigned to it. Each subvolume for which q is set will not get such a "subtree" quota group, but it is ensured that they are added to the same "subtree" quota group as their immediate parents.

It is recommended to use Q for subvolumes that typically contain further subvolumes, and where it is desirable to have accounting and quota limits on all child subvolumes together. Examples for Q are typically /home/ or /var/lib/machines/. In contrast, q should be used for subvolumes that either usually do not include further subvolumes or where no accounting and quota limits are needed that apply to all child subvolumes together. Examples for q are typically /var/ or /var/tmp/.

As with q, Q has no effect on the quota group hierarchy if the subvolume already exists, regardless of whether the subvolume already belong to a quota group or not.

p, p+

Create a named pipe (FIFO) if it does not exist yet. If suffixed with + and a file already exists where the pipe is to be created, it will be removed and be replaced by the pipe.

L, L+

Create a symlink if it does not exist yet. If suffixed with + and a file or directory already exists where the symlink is to be created, it will be removed and be replaced by the symlink. If the argument is omitted, symlinks to files with the same name residing in the directory /usr/share/factory/ are created. Note that permissions and ownership on symlinks are ignored.

c, c+

Create a character device node if it does not exist yet. If suffixed with + and a file already exists where the device node is to be created, it will be removed and be replaced by the device node. It is recommended to suffix this entry with an exclamation mark to only create static device nodes at boot, as udev will not manage static device nodes that are created at runtime.

b, b+

Create a block device node if it does not exist yet. If suffixed with + and a file already exists where the device node is to be created, it will be removed and be replaced by the device node. It is recommended to suffix this entry with an exclamation mark to only create static device nodes at boot, as udev will not manage static device nodes that are created at runtime.

C

Recursively copy a file or directory, if the destination files or directories do not exist yet or the destination directory is empty. Note that this command will not descend into subdirectories if the destination directory already exists and is not empty. Instead, the entire copy operation is skipped. If the argument is omitted, files from the source directory /usr/share/factory/ with the same name are copied. Does not follow symlinks.

x

Ignore a path during cleaning. Use this type to exclude paths from clean-up as controlled with the Age parameter. Note that lines of this type do not influence the effect of r or R lines. Lines of this type accept shell-style globs in place of normal path names.

X

Ignore a path during cleaning. Use this type to exclude paths from clean-up as controlled with the Age parameter. Unlike x, this parameter will not exclude the content if path is a directory, but only directory itself. Note that lines of this type do not influence the effect of r or R lines. Lines of this type accept shell-style globs in place of normal path names.

r

Remove a file or directory if it exists. This may not be used to remove non-empty directories, use R for that. Lines of this type accept shell-style globs in place of normal path names. Does not follow symlinks.

R

Recursively remove a path and all its subdirectories (if it is a directory). Lines of this type accept shell-style globs in place of normal path names. Does not follow symlinks.

z

Adjust the access mode, user and group ownership, and restore the SELinux security context of a file or directory, if it exists. Lines of this type accept shell-style globs in place of normal path names. Does not follow symlinks.

Z

Recursively set the access mode, user and group ownership, and restore the SELinux security context of a file or directory if it exists, as well as of its subdirectories and the files contained therein (if applicable). Lines of this type accept shell-style globs in place of normal path names. Does not follow symlinks.

t

Set extended attributes, see attr(5) for details. The argument field should take one or more assignment expressions in the form namespace.attribute=value, for examples see below. Lines of this type accept shell-style globs in place of normal path names. This can be useful for setting SMACK labels. Does not follow symlinks. Please note that extended attributes settable with this line type are a different concept from the Linux file attributes settable with h/H, see below.

T

Same as t, but operates recursively.

h

Set Linux file/directory attributes. Lines of this type accept shell-style globs in place of normal path names. The format of the argument field is [+-=][aAcCdDeijPsStTu]. The prefix + (the default one) causes the attribute(s) to be added; - causes the attribute(s) to be removed; = causes the attributes to be set exactly as the following letters. The letters "aAcCdDeijPsStTu" select the new attributes for the files, see chattr(1) for further information.

Passing only = as argument resets all the file attributes listed above. It has to be pointed out that the = prefix limits itself to the attributes corresponding to the letters listed here. All other attributes will be left untouched. Does not follow symlinks.

Please note that the Linux file attributes settable with this line type are a different concept from the extended attributes settable with t/T, see above.

H

Sames as h, but operates recursively.

a, a+

Set POSIX ACLs (access control lists), see acl(5). If suffixed with +, the specified entries will be added to the existing set. systemd-tmpfiles will automatically add the required base entries for user and group based on the access mode of the file, unless base entries already exist or are explicitly specified. The mask will be added if not specified explicitly or already present. Lines of this type accept shell-style globs in place of normal path names. This can be useful for allowing additional access to certain files. Does not follow symlinks.

A, A+

Same as a and a+, but recursive. Does not follow symlinks.

If the exclamation mark ("!") is used, this line is only safe to execute during boot, and can break a running system. Lines without the exclamation mark are presumed to be safe to execute at any time, e.g. on package upgrades. systemd-tmpfiles will take lines with an exclamation mark only into consideration, if the --boot option is given.

For example:

```
# Make sure these are created by default so that nobody else can
d /tmp/.X11-unix 1777 root root 10d
# Unlink the X11 lock files
r! /tmp/.X[0-9]*-lock
```

The second line in contrast to the first one would break a running system, and will only be executed with --boot.

If the minus sign ("-") is used, this line failing to run successfully during create (and only create) will not cause the execution of systemd-tmpfiles to return an error.

For example:

```
# Modify sysfs but don't fail if we are in a container with a read-only /proc
w- /proc/sys/vm/swappiness - - - - 10
```

If the equals sign ("=") is used, the file types of existing objects in the specified path are checked, and removed if they do not match. This includes any implicitly created parent directories (which can be either directories or directory symlinks). For example, if there is a FIFO in place of one of the parent path components it will be replaced with a directory.

Note that for all line types that result in creation of any kind of file node (i.e. f/F, d/D/v/q/Q, p, L, c/b and C) leading directories are implicitly created if needed, owned by root with an access mode of 0755. In order to create them with different modes or ownership make sure to add appropriate d lines.

### Path
The file system path specification supports simple specifier expansion, see below. The path (after expansion) must be absolute.

### Mode
The file access mode to use when creating this file or directory. If omitted or when set to "-", the default is used: 0755 for directories, 0644 for all other file objects. For z, Z lines, if omitted or when set to "-", the file access mode will not be modified. This parameter is ignored for x, r, R, L, t, and a lines.

Optionally, if prefixed with "~", the access mode is masked based on the already set access bits for existing file or directories: if the existing file has all executable bits unset, all executable bits are removed from the new access mode, too. Similarly, if all read bits are removed from the old access mode, they will be removed from the new access mode too, and if all write bits are removed, they will be removed from the new access mode too. In addition, the sticky/SUID/SGID bit is removed unless applied to a directory. This functionality is particularly useful in conjunction with Z.

### User, Group
The user and group to use for this file or directory. This may either be a numeric ID or a user/group name. If omitted or when set to "-", the user and group of the user who invokes systemd-tmpfiles is used. For z and Z lines, when omitted or when set to "-", the file ownership will not be modified. These parameters are ignored for x, r, R, L, t, and a lines.

This field should generally only reference system users/groups, i.e. users/groups that are guaranteed to be resolvable during early boot. If this field references users/groups that only become resolveable during later boot (i.e. after NIS, LDAP or a similar networked directory service become available), execution of the operations declared by the line will likely fail. Also see Notes on Resolvability of User and Group Names[1] for more information on requirements on system user/group definitions.

### Age
The date field, when set, is used to decide what files to delete when cleaning. If a file or directory is older than the current time minus the age field, it is deleted. The field format is a series of integers each followed by one of the following suffixes for the respective time units: s, m or min, h, d, w, ms, and us, meaning seconds, minutes, hours, days, weeks, milliseconds, and microseconds, respectively. Full names of the time units can be used too.

If multiple integers and units are specified, the time values are summed. If an integer is given without a unit, s is assumed.

When the age is set to zero, the files are cleaned unconditionally.

The age field only applies to lines starting with d, D, e, v, q, Q, C, x and X. If omitted or set to "-", no automatic clean-up is done.

If the age field starts with a tilde character "~", clean-up is only applied to files and directories one level inside the directory specified, but not the files and directories immediately inside it.

The age of a file system entry is determined from its last modification timestamp (mtime), its last access timestamp (atime), and (except for directories) its last status change timestamp (ctime). By default, any of these three (or two) values will prevent cleanup if it is more recent than the current time minus the age field. To restrict the deletion based on particular type of file timestamps, the age-by argument can be used.

The age-by argument overrides the timestamp types to be used for the age check. It can be specified by prefixing the age argument with a sequence of characters to specify the timestamp types and a colon (":"): "age-by...:cleanup-age". The argument can consist of a (A for directories), b (B for directories), c (C for directories), or m (M for directories). Those respectively indicate access, creation, last status change, and last modification time of a file system entry. The lower-case letter signifies that the given timestamp type should be considered for files, while the upper-case letter signifies that the given timestamp type should be considered for directories. See statx(2) file timestamp fields for more details about timestamp types.

If not specified, the age-by field defaults to abcmABM, i.e. by default all file timestamps are taken into consideration, with the exception of the last status change timestamp (ctime) for directories. This is because the aging logic itself will alter the ctime whenever it deletes a file inside it. To ensure that running the aging logic does not feed back into the next iteration of itself, ctime for directories is ignored by default.

For example:

```
# Files created and modified, and directories accessed more than
# an hour ago in "/tmp/foo/bar", are subject to time-based cleanup.
d /tmp/foo/bar - - - - bmA:1h -
```

Note that while the aging algorithm is run a 'shared' BSD file lock (see flock(2)) is taken on each directory the algorithm descends into (and each directory below that, and so on). If the aging algorithm finds a lock is already taken on some directory, it (and everything below it) is skipped. Applications may use this to temporarily exclude certain directory subtrees from the aging algorithm: the applications can take a BSD file lock themselves, and as long as they keep it aging of the directory and everything below it is disabled.

### Argument
For L lines determines the destination path of the symlink. For c and b, determines the major/minor of the device node, with major and minor formatted as integers, separated by ":", e.g. "1:3". For f, F, and w, the argument may be used to specify a short string that is written to the file, suffixed by a newline. For C, specifies the source file or directory. For t and T, determines extended attributes to be set. For a and A, determines ACL attributes to be set. For h and H, determines the file attributes to set. Ignored for all other lines.

This field can contain specifiers, see below.

## SPECIFIERS
Specifiers can be used in the "path" and "argument" fields. An unknown or unresolvable specifier is treated as invalid configuration. The following expansions are understood:

Table 1. Specifiers available

Specifier

Meaning

Details

"%a"

Architecture

A short string identifying the architecture of the local system. A string such as x86, x86-64 or arm64. See the architectures defined for ConditionArchitecture= in systemd.unit(5) for a full list.

"%A"

Operating system image version

The operating system image version identifier of the running system, as read from the IMAGE_VERSION= field of /etc/os-release. If not set, resolves to an empty string. See os-release(5) for more information.

"%b"

Boot ID

The boot ID of the running system, formatted as string. See random(4) for more information.

"%B"

Operating system build ID

The operating system build identifier of the running system, as read from the BUILD_ID= field of /etc/os-release. If not set, resolves to an empty string. See os-release(5) for more information.

"%C"

System or user cache directory

In --user mode, this is the same as $XDG_CACHE_HOME, and /var/cache otherwise.

"%g"

User group

This is the name of the group running the command. In case of the system instance this resolves to "root".

"%G"

User GID

This is the numeric GID of the group running the command. In case of the system instance this resolves to 0.

"%h"

User home directory

This is the home directory of the user running the command. In case of the system instance this resolves to "/root".

"%H"

Host name

The hostname of the running system.

"%l"

Short host name

The hostname of the running system, truncated at the first dot to remove any domain component.

"%L"

System or user log directory

In --user mode, this is the same as $XDG_CONFIG_HOME with /log appended, and /var/log otherwise.

"%m"

Machine ID

The machine ID of the running system, formatted as string. See machine-id(5) for more information.

"%M"

Operating system image identifier

The operating system image identifier of the running system, as read from the IMAGE_ID= field of /etc/os-release. If not set, resolves to an empty string. See os-release(5) for more information.

"%o"

Operating system ID

The operating system identifier of the running system, as read from the ID= field of /etc/os-release. See os-release(5) for more information.

"%S"

System or user state directory

In --user mode, this is the same as $XDG_CONFIG_HOME, and /var/lib otherwise.

"%t"

System or user runtime directory

In --user mode, this is the same $XDG_RUNTIME_DIR, and /run/ otherwise.

"%T"

Directory for temporary files

This is either /tmp or the path "$TMPDIR", "$TEMP" or "$TMP" are set to. (Note that the directory may be specified without a trailing slash.)

"%u"

User name

This is the name of the user running the command. In case of the system instance this resolves to "root".

"%U"

User UID

This is the numeric UID of the user running the command. In case of the system instance this resolves to 0.

"%v"

Kernel release

Identical to uname -r output.

"%V"

Directory for larger and persistent temporary files

This is either /var/tmp or the path "$TMPDIR", "$TEMP" or "$TMP" are set to. (Note that the directory may be specified without a trailing slash.)

"%w"

Operating system version ID

The operating system version identifier of the running system, as read from the VERSION_ID= field of /etc/os-release. If not set, resolves to an empty string. See os-release(5) for more information.

"%W"

Operating system variant ID

The operating system variant identifier of the running system, as read from the VARIANT_ID= field of /etc/os-release. If not set, resolves to an empty string. See os-release(5) for more information.

"%%"

Single percent sign

Use "%%" in place of "%" to specify a single percent sign.

## EXAMPLES
Example 1. Create directories with specific mode and ownership

screen(1), needs two directories created at boot with specific modes and ownership:

```
# /lib/tmpfiles.d/screen.conf
d /run/screens  1777 root screen 10d
d /run/uscreens 0755 root screen 10d12h
```

Contents of /run/screens and /run/uscreens will be cleaned up after 10 and 10½ days, respectively.

Example 2. Create a directory with a SMACK attribute

```
D /run/cups - - - -
t /run/cups - - - - security.SMACK64=printing user.attr-with-spaces="foo bar"

```

The directory will be owned by root and have default mode. Its contents are not subject to time based cleanup, but will be obliterated when systemd-tmpfiles --remove runs.

Example 3. Create a directory and prevent its contents from cleanup

abrt(1), needs a directory created at boot with specific mode and ownership and its content should be preserved from the automatic cleanup applied to the contents of /var/tmp:

```
# /lib/tmpfiles.d/tmp.conf
d /var/tmp 1777 root root 30d
```

```
# /lib/tmpfiles.d/abrt.conf
d /var/tmp/abrt 0755 abrt abrt -
```

Example 4. Apply clean up during boot and based on time

```
# /lib/tmpfiles.d/dnf.conf
r! /var/cache/dnf/*/*/download_lock.pid
r! /var/cache/dnf/*/*/metadata_lock.pid
r! /var/lib/dnf/rpmdb_lock.pid
e  /var/cache/dnf/ - - - 30d
```

The lock files will be removed during boot. Any files and directories in /var/cache/dnf/ will be removed after they have not been accessed in 30 days.

Example 5. Empty the contents of a cache directory on boot

```
# /lib/tmpfiles.d/krb5rcache.conf
e! /var/cache/krb5rcache - - - 0
```

Any files and subdirectories in /var/cache/krb5rcache/ will be removed on boot. The directory will not be created.

## /RUN/ AND /VAR/RUN/
/var/run/ is a deprecated symlink to /run/, and applications should use the latter. systemd-tmpfiles will warn if /var/run/ is used.

## SEE ALSO
systemd(1), systemd-tmpfiles(8), systemd-delta(1), systemd.exec(5), attr(5), getfattr(1), setfattr(1), setfacl(1), getfacl(1), chattr(1), btrfs-subvolume(8), btrfs-qgroup(8)

## NOTES
1.

Notes on Resolvability of User and Group Names

https://systemd.io/UIDS-GIDS/#notes-on-resolvability-of-user-and-group-names


user@.service

package: systemd

title: user@.service(5)

summary: System units to start the user manager

text:
# user@.service(5)

## NAME
user@.service, user-runtime-dir@.service, systemd-user-runtime-dir - System units to start the user manager

## SYNOPSIS
user@UID.service

user-runtime-dir@UID.service

/lib/systemd/systemd-user-runtime-dir

user-UID.slice

## DESCRIPTION
The systemd(1) system manager (PID 1) starts user manager instances as user@UID.service, with the user's numerical UID used as the instance identifier. These instances use the same executable as the system manager, but running in a mode where it starts a different set of units. Each systemd --user instance manages a hierarchy of units specific to that user. See systemd(1) for a discussion of units and systemd.special(7) for a list of units that form the basis of the unit hierarchies of system and user units.

user@UID.service is accompanied by the system unit user-runtime-dir@UID.service, which creates the user's runtime directory /run/user/UID, and then removes it when this unit is stopped. user-runtime-dir@UID.service executes the systemd-user-runtime-dir binary to do the actual work.

User processes may be started by the user@.service instance, in which case they will be part of that unit in the system hierarchy. They may also be started elsewhere, for example by sshd(8) or a display manager like gdm, in which case they form a .scope unit (see systemd.scope(5)). Both user@UID.service and the scope units are collected under the user-UID.slice.

Individual user-UID.slice slices are collected under user.slice, see systemd.special(7).

## CONTROLLING RESOURCES FOR LOGGED-IN USERS
Options that control resources available to logged-in users can be configured at a few different levels. As described in the previous section, user.slice contains processes of all users, so any resource limits on that slice apply to all users together. The usual way to configure them would be through drop-ins, e.g. /etc/systemd/system/user.slice.d/resources.conf.

The processes of a single user are collected under user-UID.slice. Resource limits for that user can be configured through drop-ins for that unit, e.g. /etc/systemd/system/user-1000.slice.d/resources.conf. If the limits should apply to all users instead, they may be configured through drop-ins for the truncated unit name, user-.slice. For example, configuration in /etc/systemd/system/user-.slice.d/resources.conf is included in all user-UID.slice units, see systemd.unit(5) for a discussion of the drop-in mechanism.

When a user logs in and a .scope unit is created for the session (see previous section), the creation of the scope may be managed through pam_systemd(8). This PAM module communicates with systemd-logind(8) to create the session scope and provide access to hardware resources. Resource limits for the scope may be configured through the PAM module configuration, see pam_systemd(8). Configuring them through the normal unit configuration is also possible, but since the name of the slice unit is generally unpredictable, this is less useful.

In general any resources that apply to units may be set for user@UID.service and the slice units discussed above, see systemd.resource-control(5) for an overview.

## EXAMPLES
Example 1. Hierarchy of control groups with two logged in users

```
$ systemd-cgls
Control group /:
-.slice
├─user.slice
│ ├─user-1000.slice
│ │ ├─user@1000.service
│ │ │ ├─pulseaudio.service
│ │ │ │ └─2386 /usr/bin/pulseaudio --daemonize=no
│ │ │ └─gnome-terminal-server.service
│ │ │   └─init.scope
│ │ │     ├─ 4127 /usr/libexec/gnome-terminal-server
│ │ │     └─ 4198 zsh
│ │ ...
│ │ └─session-4.scope
│ │   ├─ 1264 gdm-session-worker [pam/gdm-password]
│ │   ├─ 2339 /usr/bin/gnome-shell
│ │   ...
│ │ ├─session-19.scope
│ │   ├─6497 sshd: zbyszek [priv]
│ │   ├─6502 sshd: zbyszek@pts/6
│ │   ├─6509 -zsh
│ │   └─6602 systemd-cgls --no-pager
│ ...
│ └─user-1001.slice
│   ├─session-20.scope
│   │ ├─6675 sshd: guest [priv]
│   │ ├─6708 sshd: guest@pts/6
│   │ └─6717 -bash
│   └─user@1001.service
│     ├─init.scope
│     │ ├─6680 /usr/lib/systemd/systemd --user
│     │ └─6688 (sd-pam)
│     └─sleep.service
│       └─6706 /usr/bin/sleep 30
...
```

User with UID 1000 is logged in using gdm (session-4.scope) and ssh(1) (session-19.scope), and also has a user manager instance running (user@1000.service). User with UID 1001 is logged in using ssh (session-20.scope) and also has a user manager instance running (user@1001.service). Those are all (leaf) system units, and form part of the slice hierarchy, with user-1000.slice and user-1001.slice below user.slice. User units are visible below the user@.service instances (pulseaudio.service, gnome-terminal-server.service, init.scope, sleep.service).

Example 2. Default user resource limits

```
$ systemctl cat user-1000.slice
# /lib/systemd/system/user-.slice.d/10-defaults.conf
# ...
[Unit]
Description=User Slice of UID %j
After=systemd-user-sessions.service
[Slice]
TasksMax=33%
```

The user-UID.slice units by default don't have a unit file. The resource limits are set through a drop-in, which can be easily replaced or extended following standard drop-in mechanisms discussed in the first section.

## SEE ALSO
systemd(1), systemd.service(5), systemd.slice(5), systemd.resource-control(5), systemd.exec(5), systemd.special(7), pam(8)


vconsole.conf

title: vconsole.conf(5)

text:
# vconsole.conf(5)

## NAME
vconsole.conf - Configuration file for the virtual console

## SYNOPSIS
/etc/vconsole.conf

## DESCRIPTION
The /etc/vconsole.conf file configures the virtual console, i.e. keyboard mapping and console font. It is applied at boot by udev using 90-vconsole.rules file. You can safely mask this file if you want to avoid this kind of initialization.

The basic file format of the vconsole.conf is a newline-separated list of environment-like shell-compatible variable assignments. It is possible to source the configuration from shell scripts, however, beyond mere variable assignments no shell features are supported, allowing applications to read the file without implementing a shell compatible execution engine.

Note that the kernel command line options vconsole.keymap=, vconsole.keymap_toggle=, vconsole.font=, vconsole.font_map=, vconsole.font_unimap= may be used to override the console settings at boot.

Depending on the operating system other configuration files might be checked for configuration of the virtual console as well, however only as fallback.

/etc/vconsole.conf is usually created and updated using systemd-localed.service(8). localectl(1) may be used to instruct systemd-localed.service to query or update configuration.

## OPTIONS
The following options are understood:

KEYMAP=, KEYMAP_TOGGLE=

Configures the key mapping table for the keyboard. KEYMAP= defaults to "us" if not set. The KEYMAP_TOGGLE= can be used to configure a second toggle keymap and is by default unset.

FONT=, FONT_MAP=, FONT_UNIMAP=

Configures the console font, the console map and the unicode font map.

## KERNEL COMMAND LINE
A few configuration parameters from vconsole.conf may be overridden on the kernel command line:

vconsole.keymap=, vconsole.keymap_toggle=

Overrides KEYMAP= and KEYMAP_TOGGLE=.

vconsole.font=, vconsole.font_map=, vconsole.font_unimap=

Overrides FONT=, FONT_MAP=, and FONT_UNIMAP=.

## EXAMPLE
Example 1. German keyboard and console

/etc/vconsole.conf:

```
KEYMAP=de-latin1
FONT=eurlatgr
```

## SEE ALSO
systemd(1), systemd-vconsole-setup.service(8), loadkeys(1), setfont(8), locale.conf(5), systemd-localed.service(8)


veritytab

title: veritytab(5)

summary: Configuration for verity block devices

text:
# veritytab(5)

## NAME
veritytab - Configuration for verity block devices

## SYNOPSIS
/etc/veritytab

## DESCRIPTION
The /etc/veritytab file describes verity protected block devices that are set up during system boot.

Empty lines and lines starting with the "#" character are ignored. Each of the remaining lines describes one verity protected block device. Fields are delimited by white space.

Each line is in the form

```
volume-name data-device hash-device roothash options
```

The first four fields are mandatory, the remaining one is optional.

The first field contains the name of the resulting verity volume; its block device is set up below /dev/mapper/.

The second field contains a path to the underlying block data device, or a specification of a block device via "UUID=" followed by the UUID.

The third field contains a path to the underlying block hash device, or a specification of a block device via "UUID=" followed by the UUID.

The fourth field is the "roothash" in hexadecimal.

The fifth field, if present, is a comma-delimited list of options. The following options are recognized:

ignore-corruption, restart-on-corruption, panic-on-corruption

Defines what to do if a data verity problem is detected (data corruption). Without these options kernel fails the IO operation with I/O error. With "--ignore-corruption" option the corruption is only logged. With "--restart-on-corruption" or "--panic-on-corruption" the kernel is restarted (panicked) immediately. (You have to provide way how to avoid restart loops.)

ignore-zero-blocks

Instruct kernel to not verify blocks that are expected to contain zeroes and always directly return zeroes instead. WARNING: Use this option only in very specific cases. This option is available since Linux kernel version 4.5.

check-at-most-once

Instruct kernel to verify blocks only the first time they are read from the data device, rather than every time. WARNING: It provides a reduced level of security because only offline tampering of the data device's content will be detected, not online tampering. This option is available since Linux kernel version 4.17.

root-hash-signature=

A base64 string encoding the root hash signature prefixed by "base64:" or a path to roothash signature file used to verify the root hash (in kernel). This feature requires Linux kernel version 5.4 or more recent.

_netdev

Marks this veritysetup device as requiring network. It will be started after the network is available, similarly to systemd.mount(5) units marked with _netdev. The service unit to set up this device will be ordered between remote-fs-pre.target and remote-veritysetup.target, instead of veritysetup-pre.target and veritysetup.target. Hint: if this device is used for a mount point that is specified in fstab(5), the _netdev option should also be used for the mount point. Otherwise, a dependency loop might be created where the mount point will be pulled in by local-fs.target, while the service to configure the network is usually only started after the local file system has been mounted.

noauto

This device will not be added to veritysetup.target. This means that it will not be automatically enabled on boot, unless something else pulls it in. In particular, if the device is used for a mount point, it'll be enabled automatically during boot, unless the mount point itself is also disabled with noauto.

nofail

This device will not be a hard dependency of veritysetup.target. It'll still be pulled in and started, but the system will not wait for the device to show up and be enabled, and boot will not fail if this is unsuccessful. Note that other units that depend on the enabled device may still fail. In particular, if the device is used for a mount point, the mount point itself also needs to have the nofail option, or the boot will fail if the device is not enabled successfully.

x-initrd.attach

Setup this verity protected block device in the initramfs, similarly to systemd.mount(5) units marked with x-initrd.mount. Although it's not necessary to mark the mount entry for the root file system with x-initrd.mount, x-initrd.attach is still recommended with the verity protected block device containing the root file system as otherwise systemd will attempt to detach the device during the regular system shutdown while it's still in use. With this option the device will still be detached but later after the root file system is unmounted.

All other verity protected block devices that contain file systems mounted in the initramfs should use this option.

At early boot and when the system manager configuration is reloaded, this file is translated into native systemd units by systemd-veritysetup-generator(8).

## EXAMPLES
Example 1. /etc/veritytab example

Set up two verity protected block devices. One using device blocks, another using files.

```
usr  PARTUUID=783e45ae-7aa3-484a-beef-a80ff9c19cbb PARTUUID=21dc1dfe-4c33-8b48-98a9-918a22eb3e37 36e3f740ad502e2c25e2a23d9c7c17bf0fdad2300b7580842d4b7ec1fb0fa263 auto
data /etc/data /etc/hash a5ee4b42f70ae1f46a08a7c92c2e0a20672ad2f514792730f5d49d7606ab8fdf auto
```

## SEE ALSO
systemd(1), systemd-veritysetup@.service(8), systemd-veritysetup-generator(8), fstab(5), veritysetup(8),


loader.conf

package: systemd-boot-efi

title: loader.conf(5)

summary: Configuration file for systemd\-boot

text:
# loader.conf(5)

## NAME
loader.conf - Configuration file for systemd-boot

## SYNOPSIS
ESP/loader/loader.conf, ESP/loader/entries/*.conf

## DESCRIPTION
systemd-boot(7) will read ESP/loader/loader.conf and any files with the ".conf" extension under ESP/loader/entries/ on the EFI system partition (ESP).

Each configuration file must consist of an option name, followed by whitespace, and the option value. "#" may be used to start a comment line. Empty and comment lines are ignored.

Boolean arguments may be written as "yes"/"y"/"true"/"1" or "no"/"n"/"false"/"0".

## OPTIONS
The following configuration options in loader.conf are understood:

default

A glob pattern to select the default entry. The default entry may be changed in the boot menu itself, in which case the name of the selected entry will be stored as an EFI variable, overriding this option.

timeout

How long the boot menu should be shown before the default entry is booted, in seconds. This may be changed in the boot menu itself and will be stored as an EFI variable in that case, overriding this option. If the timeout is disabled, the default entry will be booted immediately. The menu can be shown by pressing and holding a key before systemd-boot is launched.

console-mode

This option configures the resolution of the console. Takes a number or one of the special values listed below. The following values may be used: 0

Standard UEFI 80x25 mode

1

80x50 mode, not supported by all devices

2

the first non-standard mode provided by the device firmware, if any

auto

Pick a suitable mode automatically using heuristics

max

Pick the highest-numbered available mode

keep

Keep the mode selected by firmware (the default)

editor

Takes a boolean argument. Enable (the default) or disable the editor. The editor should be disabled if the machine can be accessed by unauthorized persons.

auto-entries

Takes a boolean argument. Enable (the default) or disable entries for other boot entries found on the boot partition. In particular, this may be useful when loader entries are created to show replacement descriptions for those entries.

auto-firmware

Takes a boolean argument. Enable (the default) or disable the "Reboot into firmware" entry.

random-seed-mode

Takes one of "off", "with-system-token" and "always". If "off" no random seed data is read off the ESP, nor passed to the OS. If "with-system-token" (the default) systemd-boot will read a random seed from the ESP (from the file /loader/random-seed) only if the LoaderSystemToken EFI variable is set, and then derive the random seed to pass to the OS from the combination. If "always" the boot loader will do so even if LoaderSystemToken is not set. This mode is useful in environments where protection against OS image reuse is not a concern, and the random seed shall be used even with no further setup in place. Use bootctl random-seed to initialize both the random seed file in the ESP and the system token EFI variable. See Random Seeds[1] for further information.

## EXAMPLE

```
# /boot/efi/loader/loader.conf
timeout 0
default 01234567890abcdef1234567890abdf0-*
editor no

```

The menu will not be shown by default (the menu can still be shown by pressing and holding a key during boot). One of the entries with files with a name starting with "01234567890abcdef1234567890abdf0-" will be selected by default. If more than one entry matches, the one with the highest priority will be selected (generally the one with the highest version number). The editor will be disabled, so it is not possible to alter the kernel command line.

## SEE ALSO
systemd-boot(7), bootctl(1)

## NOTES
1.

Random Seeds

https://systemd.io/RANDOM_SEEDS


bootchart.conf

package: systemd-bootchart

title: bootchart.conf(5)

text:
# bootchart.conf(5)

## NAME
bootchart.conf, bootchart.conf.d - Boot performance analysis graphing tool configuration files

## SYNOPSIS
/etc/systemd/bootchart.conf

/etc/systemd/bootchart.conf.d/*.conf

/run/systemd/bootchart.conf.d/*.conf

/lib/systemd/bootchart.conf.d/*.conf

## DESCRIPTION
When starting, systemd-bootchart will read the configuration file /etc/systemd/bootchart.conf, followed by the files in the bootchart.conf.d directories. These configuration files determine logging parameters and graph output.

## CONFIGURATION DIRECTORIES AND PRECEDENCE
The default configuration is defined during compilation, so a configuration file is only needed when it is necessary to deviate from those defaults. By default, the configuration file in /etc/systemd/ contains commented out entries showing the defaults as a guide to the administrator. This file can be edited to create local overrides.

When packages need to customize the configuration, they can install configuration snippets in /lib/systemd/*.conf.d/. Files in /etc/ are reserved for the local administrator, who may use this logic to override the configuration files installed by vendor packages. The main configuration file is read before any of the configuration directories, and has the lowest precedence; entries in a file in any configuration directory override entries in the single configuration file. Files in the *.conf.d/ configuration subdirectories are sorted by their filename in lexicographic order, regardless of which of the subdirectories they reside in. If multiple files specify the same option, the entry in the file with the lexicographically latest name takes precedence. It is recommended to prefix all filenames in those subdirectories with a two-digit number and a dash, to simplify the ordering of the files.

To disable a configuration file supplied by the vendor, the recommended way is to place a symlink to /dev/null in the configuration directory in /etc/, with the same filename as the vendor configuration file.

## OPTIONS
Samples=500

Configure the amount of samples to record in total before bootchart exits. Each sample will record at intervals defined by Frequency=.

Frequency=25

Configure the sample log frequency. This can be a fractional number, but must be larger than 0.0. Most systems can cope with values under 25-50 without impacting boot time severely.

Relative=no

Configures whether the left axis of the output graph equals time=0.0 (CLOCK_MONOTONIC start). This is useful for using bootchart at post-boot time to profile an already booted system, otherwise the graph would become extremely large. If set to yes, the horizontal axis starts at the first recorded sample instead of time=0.0.

Filter=no

Configures whether the resulting graph should omit tasks that did not contribute significantly to the boot. Processes that are too short-lived (only seen in one sample) or that do not consume any significant CPU time (less than 0.001sec) will not be displayed in the output graph.

Output=[path]

Configures the output directory for writing the graphs. By default, bootchart writes the graphs to /run/log.

Init=[path]

Configures bootchart to run a non-standard binary instead of /lib/systemd/systemd. This option is only relevant if bootchart was invoked from the kernel command line with init=/lib/systemd/systemd-bootchart.

PlotMemoryUsage=no

If set to yes, enables logging and graphing of processes' PSS memory consumption.

PlotEntropyGraph=no

If set to yes, enables logging and graphing of the kernel random entropy pool size.

ScaleX=100

Horizontal scaling factor for all variable graph components.

ScaleY=20

Vertical scaling factor for all variable graph components.

ControlGroup=no

Display process control group.

Cmdline=no

Display the full command line of each process.

## SEE ALSO
systemd-bootchart(1), systemd.directives(7)


machine-id

package: systemd-container

title: machine-id(5)

summary: Local machine ID configuration file

text:
# machine-id(5)

## NAME
machine-id - Local machine ID configuration file

## SYNOPSIS
/etc/machine-id

## DESCRIPTION
The /etc/machine-id file contains the unique machine ID of the local system that is set during installation or boot. The machine ID is a single newline-terminated, hexadecimal, 32-character, lowercase ID. When decoded from hexadecimal, this corresponds to a 16-byte/128-bit value. This ID may not be all zeros.

The machine ID is usually generated from a random source during system installation or first boot and stays constant for all subsequent boots. Optionally, for stateless systems, it is generated during runtime during early boot if necessary.

The machine ID may be set, for example when network booting, with the systemd.machine_id= kernel command line parameter or by passing the option --machine-id= to systemd. An ID specified in this manner has higher priority and will be used instead of the ID stored in /etc/machine-id.

The machine ID does not change based on local or network configuration or when hardware is replaced. Due to this and its greater length, it is a more useful replacement for the gethostid(3) call that POSIX specifies.

This machine ID adheres to the same format and logic as the D-Bus machine ID.

This ID uniquely identifies the host. It should be considered "confidential", and must not be exposed in untrusted environments, in particular on the network. If a stable unique identifier that is tied to the machine is needed for some application, the machine ID or any part of it must not be used directly. Instead the machine ID should be hashed with a cryptographic, keyed hash function, using a fixed, application-specific key. That way the ID will be properly unique, and derived in a constant way from the machine ID but there will be no way to retrieve the original machine ID from the application-specific one. The sd_id128_get_machine_app_specific(3) API provides an implementation of such an algorithm.

## INITIALIZATION
Each machine should have a non-empty ID in normal operation. The ID of each machine should be unique. To achieve those objectives, /etc/machine-id can be initialized in a few different ways.

For normal operating system installations, where a custom image is created for a specific machine, /etc/machine-id should be populated during installation.

systemd-machine-id-setup(8) may be used by installer tools to initialize the machine ID at install time, but /etc/machine-id may also be written using any other means.

For operating system images which are created once and used on multiple machines, for example for containers or in the cloud, /etc/machine-id should be either missing or an empty file in the generic file system image (the difference between the two options is described under "First Boot Semantics" below). An ID will be generated during boot and saved to this file if possible. Having an empty file in place is useful because it allows a temporary file to be bind-mounted over the real file, in case the image is used read-only.

systemd-firstboot(8) may be used to initialize /etc/machine-id on mounted (but not booted) system images.

When a machine is booted with systemd(1) the ID of the machine will be established. If systemd.machine_id= or --machine-id= options (see first section) are specified, this value will be used. Otherwise, the value in /etc/machine-id will be used. If this file is empty or missing, systemd will attempt to use the D-Bus machine ID from /var/lib/dbus/machine-id, the value of the kernel command line option container_uuid, the KVM DMI product_uuid or the devicetree vm,uuid (on KVM systems), and finally a randomly generated UUID.

After the machine ID is established, systemd(1) will attempt to save it to /etc/machine-id. If this fails, it will attempt to bind-mount a temporary file over /etc/machine-id. It is an error if the file system is read-only and does not contain a (possibly empty) /etc/machine-id file.

systemd-machine-id-commit.service(8) will attempt to write the machine ID to the file system if /etc/machine-id or /etc/ are read-only during early boot but become writable later on.

## FIRST BOOT SEMANTICS
/etc/machine-id is used to decide whether a boot is the first one. The rules are as follows:

1.If /etc/machine-id does not exist, this is a first boot. During early boot, systemd will write "uninitialized\n" to this file and overmount a temporary file which contains the actual machine ID. Later (after first-boot-complete.target has been reached), the real machine ID will be written to disk.

2.If /etc/machine-id contains the string "uninitialized", a boot is also considered the first boot. The same mechanism as above applies.

3.If /etc/machine-id exists and is empty, a boot is not considered the first boot. systemd will still bind-mount a file containing the actual machine-id over it and later try to commit it to disk (if /etc/ is writable).

4.If /etc/machine-id already contains a valid machine-id, this is not a first boot.

If by any of the above rules, a first boot is detected, units with ConditionFirstBoot=yes will be run.

## RELATION TO OSF UUIDS
Note that the machine ID historically is not an OSF UUID as defined by RFC 4122[1], nor a Microsoft GUID; however, starting with systemd v30, newly generated machine IDs do qualify as Variant 1 Version 4 UUIDs, as per RFC 4122.

In order to maintain compatibility with existing installations, an application requiring a strictly RFC 4122 compliant UUID should decode the machine ID, and then (non-reversibly) apply the following operations to turn it into a valid RFC 4122 Variant 1 Version 4 UUID. With "id" being an unsigned character array:

```
/* Set UUID version to 4 --- truly random generation */
id[6] = (id[6] & 0x0F) | 0x40;
/* Set the UUID variant to DCE */
id[8] = (id[8] & 0x3F) | 0x80;
```

(This code is inspired by "generate_random_uuid()" of drivers/char/random.c from the Linux kernel sources.)

## HISTORY
The simple configuration file format of /etc/machine-id originates in the /var/lib/dbus/machine-id file introduced by D-Bus. In fact, this latter file might be a symlink to /etc/machine-id.

## SEE ALSO
systemd(1), systemd-machine-id-setup(8), gethostid(3), hostname(5), machine-info(5), os-release(5), sd-id128(3), sd_id128_get_machine(3), systemd-firstboot(8)

## NOTES
1.

RFC 4122

https://tools.ietf.org/html/rfc4122


machine-info

title: machine-info(5)

summary: Local machine information file

text:
# machine-info(5)

## NAME
machine-info - Local machine information file

## SYNOPSIS
/etc/machine-info

## DESCRIPTION
The /etc/machine-info file contains machine metadata.

The basic file format of machine-info is a newline-separated list of environment-like shell-compatible variable assignments. It is possible to source the configuration from shell scripts, however, beyond mere variable assignments no shell features are supported, allowing applications to read the file without implementing a shell compatible execution engine.

/etc/machine-info contains metadata about the machine that is set by the user or administrator. The settings configured here have the highest precedence. When not set, appropriate values may be determined automatically, based on the information about the hardware or other configuration files. It is thus completely fine for this file to not be present.

You may use hostnamectl(1) to change the settings of this file from the command line.

## OPTIONS
The following machine metadata parameters may be set using /etc/machine-info:

PRETTY_HOSTNAME=

A pretty human-readable UTF-8 machine identifier string. This should contain a name like "Lennart's Laptop" which is useful to present to the user and does not suffer by the syntax limitations of internet domain names. If possible, the internet hostname as configured in /etc/hostname should be kept similar to this one. Example: if this value is "Lennart's Computer" an Internet hostname of "lennarts-computer" might be a good choice. If this parameter is not set, an application should fall back to the Internet hostname for presentation purposes.

ICON_NAME=

An icon identifying this machine according to the XDG Icon Naming Specification[1]. If this parameter is not set, an application should fall back to "computer" or a similar icon name.

CHASSIS=

The chassis type. Currently, the following chassis types are defined: "desktop", "laptop", "convertible", "server", "tablet", "handset", "watch", and "embedded", as well as the special chassis types "vm" and "container" for virtualized systems that lack an immediate physical chassis. Note that most systems allow detection of the chassis type automatically (based on firmware information or suchlike). This setting should only be used to override a misdetection or to manually configure the chassis type where automatic detection is not available.

DEPLOYMENT=

Describes the system deployment environment. One of the following is suggested: "development", "integration", "staging", "production".

LOCATION=

Describes the system location if applicable and known. Takes a human-friendly, free-form string. This may be as generic as "Berlin, Germany" or as specific as "Left Rack, 2nd Shelf".

## EXAMPLE

```
PRETTY_HOSTNAME="Lennart's Tablet"
ICON_NAME=computer-tablet
CHASSIS=tablet
DEPLOYMENT=production
```

## SEE ALSO
systemd(1), os-release(5), hostname(5), machine-id(5), hostnamectl(1), systemd-hostnamed.service(8)

## NOTES
1.

XDG Icon Naming Specification

http://standards.freedesktop.org/icon-naming-spec/icon-naming-spec-latest.html


title: org.freedesktop.import1(5)

summary: The D\-Bus interface of systemd\-importd

text:
# org.freedesktop.import1(5)

## NAME
org.freedesktop.import1 - The D-Bus interface of systemd-importd

## INTRODUCTION
systemd-importd.service(8) is a system service which may be used to import, export and download additional system images. These images can be used by tools such as systemd-nspawn(1) to run local containers. The service is used as the backend for machinectl pull-raw, machinectl pull-tar and related commands. This page describes the D-Bus interface.

Note that systemd-importd.service(8) is mostly a small companion service for systemd-machined.service(8). Many operations to manipulate local container and VM images are hence available via the systemd-machined D-Bus API, c.f. org.freedesktop.machine1(5).

## THE MANAGER OBJECT
The service exposes the following interfaces on the Manager object on the bus:

```
node /org/freedesktop/import1 {

  interface org.freedesktop.import1.Manager {

    methods:

      ImportTar(in  h fd,

                in  s local_name,

                in  b force,

                in  b read_only,

                out u transfer_id,

                out o transfer_path);

      ImportRaw(in  h fd,

                in  s local_name,

                in  b force,

                in  b read_only,

                out u transfer_id,

                out o transfer_path);

      ImportFileSystem(in  h fd,

                       in  s local_name,

                       in  b force,

                       in  b read_only,

                       out u transfer_id,

                       out o transfer_path);

      ExportTar(in  s local_name,

                in  h fd,

                in  s format,

                out u transfer_id,

                out o transfer_path);

      ExportRaw(in  s local_name,

                in  h fd,

                in  s format,

                out u transfer_id,

                out o transfer_path);

      PullTar(in  s url,

              in  s local_name,

              in  s verify_mode,

              in  b force,

              out u transfer_id,

              out o transfer_path);

      PullRaw(in  s url,

              in  s local_name,

              in  s verify_mode,

              in  b force,

              out u transfer_id,

              out o transfer_path);

      ListTransfers(out a(usssdo) transfers);

      CancelTransfer(in  u transfer_id);

    signals:

      TransferNew(u transfer_id,

                  o transfer_path);

      TransferRemoved(u transfer_id,

                      o transfer_path,

                      s result);

  };

  interface org.freedesktop.DBus.Peer { ... };

  interface org.freedesktop.DBus.Introspectable { ... };

  interface org.freedesktop.DBus.Properties { ... };
};

```

### Methods
ImportTar() and ImportRaw() import a system image and place it into /var/lib/machines/. The first argument should be a file descriptor (opened for reading) referring to the tar or raw file to import. It should reference a file on disk, a pipe or a socket. When ImportTar() is used the file descriptor should refer to a tar file, optionally compressed with gzip(1), bzip2(1), or xz(1). systemd-importd will detect the used compression scheme (if any) automatically. When ImportRaw() is used the file descriptor should refer to a raw or qcow2 disk image containing an MBR or GPT disk label, also optionally compressed with gzip, bzip2 or xz. In either case, if the file is specified as a file descriptor on disk, progress information is generated for the import operation (as in that case we know the total size on disk). If a socket or pipe is specified, progress information is not available. The file descriptor argument is followed by a local name for the image. This should be a name suitable as a hostname and will be used to name the imported image below /var/lib/machines/. A tar import is placed as a directory tree or a btrfs(8) subvolume below /var/lib/machines/ under the specified name with no suffix appended. A raw import is placed as a file in /var/lib/machines/ with the .raw suffix appended. If the force argument is true, any pre-existing image with the same name is removed before starting the operation. Otherwise, the operation fails if an image with the same name already exists. Finally, the read_only argument controls whether to create a writable or read-only image. Both methods return immediately after starting the import, with the import transfer ongoing. They return a pair of transfer identifier and object path, which may be used to retrieve progress information about the transfer or to cancel it. The transfer identifier is a simple numeric identifier, the object path references an org.freedesktop.import1.Transfer object, see below. Listen for a TransferRemoved signal for the transfer ID in order to detect when a transfer is complete. The returned transfer object is useful to determine the current progress or log output of the ongoing import operation.

ExportTar() and ExportRaw() implement the reverse operation, and may be used to export a system image in order to place it in a tar or raw image. They take the machine name to export as their first parameter, followed by a file descriptor (opened for writing) where the tar or raw file will be written. It may either reference a file on disk or a pipe/socket. The third argument specifies in which compression format to write the image. It takes one of "uncompressed", "xz", "bzip2" or "gzip", depending on which compression scheme is required. The image written to the specified file descriptor will be a tar file in case of ExportTar() or a raw disk image in case of ExportRaw(). Note that currently raw disk images may not be exported as tar files, and vice versa. This restriction might be lifted eventually. The method returns a transfer identifier and object path for cancelling or tracking the export operation, similar to ImportTar() or ImportRaw() as described above.

PullTar() and PullRaw() may be used to download, verify and import a system image from a URL. They take an URL argument which should point to a tar or raw file on the "http://" or "https://" protocols, possibly compressed with xz, bzip2 or gzip. The second argument is a local name for the image. It should be suitable as a hostname, similar to the matching argument of the ImportTar() and ImportRaw() methods above. The third argument indicates the verification mode for the image. It may be one of "no", "checksum", "signature". "no" turns off any kind of verification of the image; "checksum" looks for a SHA256SUM file next to the downloaded image and verifies any SHA256 hash value in that file against the image; "signature" does the same but also tries to authenticate the SHA256SUM file via gpg(8) first. The last argument indicates whether to replace a possibly pre-existing image with the same local name (if "true"), or whether to fail (if "false"). Like the import and export calls above, these calls return a pair of transfer identifier and object path for the ongoing download.

ListTransfers() returns a list of ongoing import, export or download operations as created with the six calls described above. It returns an array of structures which consist of the numeric transfer identifier, a string indicating the operation (one of "import-tar", "import-raw", "export-tar", "export-raw", "pull-tar" or "pull-raw"), a string describing the remote file (in case of download operations this is the source URL, in case of import/export operations this is a short string describing the file descriptor passed in), a string with the local machine image name, a progress value between 0.0 (for 0%) and 1.0 (for 100%), as well as the transfer object path.

CancelTransfer() may be used to cancel an ongoing import, export or download operation. Simply specify the transfer identifier to cancel the ongoing operation.

### Signals
The TransferNew signal is generated each time a new transfer is started with the import, export or download calls described above. It carries the transfer ID and object path that have just been created.

The TransferRemoved signal is sent each time a transfer finishes, is canceled or fails. It also carries the transfer ID and object path, followed by a string indicating the result of the operation, which is one of "done" (on success), "canceled" or "failed".

## THE TRANSFER OBJECT

```
node /org/freedesktop/import1/transfer/_1 {

  interface org.freedesktop.import1.Transfer {

    methods:

      Cancel();

    signals:

      LogMessage(u priority,

                 s line);

    properties:

      @org.freedesktop.DBus.Property.EmitsChangedSignal("const")

      readonly u Id = ...;

      @org.freedesktop.DBus.Property.EmitsChangedSignal("const")

      readonly s Local = '...';

      @org.freedesktop.DBus.Property.EmitsChangedSignal("const")

      readonly s Remote = '...';

      @org.freedesktop.DBus.Property.EmitsChangedSignal("const")

      readonly s Type = '...';

      @org.freedesktop.DBus.Property.EmitsChangedSignal("const")

      readonly s Verify = '...';

      @org.freedesktop.DBus.Property.EmitsChangedSignal("false")

      readonly d Progress = ...;

  };

  interface org.freedesktop.DBus.Peer { ... };

  interface org.freedesktop.DBus.Introspectable { ... };

  interface org.freedesktop.DBus.Properties { ... };
};

```

### Methods
The Cancel() method may be used to cancel the transfer. It takes no parameters. This method is pretty much equivalent to the CancelTransfer() method on the Manager interface (see above), but is exposed on the Transfer object itself instead of taking a transfer ID.

### Properties
The Id property exposes the numeric transfer ID of the transfer object.

The Local, Remote and Type properties expose the local container name of this transfer, the remote source (in case of download: the URL, in case of import/export: a string describing the file descriptor passed in), and the type of operation (see the Manager's ListTransfer() method above for an explanation of the possible values).

The Verify property exposes the selected verification setting and is only defined for download operations (see above).

The Progress property exposes the current progress of the transfer as a value between 0.0 and 1.0. To show a progress bar on screen we recommend to query this value in regular intervals, for example every 500 ms or so.

## EXAMPLES
Example 1. Introspect org.freedesktop.import1.Manager on the bus

```
$ gdbus introspect --system \

  --dest org.freedesktop.import1 \

  --object-path /org/freedesktop/import1

```

Example 2. Introspect org.freedesktop.import1.Transfer on the bus

```
$ gdbus introspect --system \

  --dest org.freedesktop.import1 \

  --object-path /org/freedesktop/import1/transfer/_1

```

## VERSIONING
These D-Bus interfaces follow the usual interface versioning guidelines[1].

## NOTES
1.

the usual interface versioning guidelines

http://0pointer.de/blog/projects/versioning-dbus.html


title: org.freedesktop.machine1(5)

summary: The D\-Bus interface of systemd\-machined

text:
# org.freedesktop.machine1(5)

## NAME
org.freedesktop.machine1 - The D-Bus interface of systemd-machined

## INTRODUCTION
systemd-machined.service(8) is a system service that keeps track of locally running virtual machines and containers. This page describes the D-Bus interface.

## THE MANAGER OBJECT
The service exposes the following interfaces on the Manager object on the bus:

```
node /org/freedesktop/machine1 {

  interface org.freedesktop.machine1.Manager {

    methods:

      GetMachine(in  s name,

                 out o machine);

      GetImage(in  s name,

               out o image);

      GetMachineByPID(in  u pid,

                      out o machine);

      ListMachines(out a(ssso) machines);

      ListImages(out a(ssbttto) images);

      CreateMachine(in  s name,

                    in  ay id,

                    in  s service,

                    in  s class,

                    in  u leader,

                    in  s root_directory,

                    in  a(sv) scope_properties,

                    out o path);

      CreateMachineWithNetwork(in  s name,

                               in  ay id,

                               in  s service,

                               in  s class,

                               in  u leader,

                               in  s root_directory,

                               in  ai ifindices,

                               in  a(sv) scope_properties,

                               out o path);

      RegisterMachine(in  s name,

                      in  ay id,

                      in  s service,

                      in  s class,

                      in  u leader,

                      in  s root_directory,

                      out o path);

      RegisterMachineWithNetwork(in  s name,

                                 in  ay id,

                                 in  s service,

                                 in  s class,

                                 in  u leader,

                                 in  s root_directory,

                                 in  ai ifindices,

                                 out o path);

      UnregisterMachine(in  s name);

      TerminateMachine(in  s id);

      KillMachine(in  s name,

                  in  s who,

                  in  i signal);

      GetMachineAddresses(in  s name,

                          out a(iay) addresses);

      GetMachineOSRelease(in  s name,

                          out a{ss} fields);

      OpenMachinePTY(in  s name,

                     out h pty,

                     out s pty_path);

      OpenMachineLogin(in  s name,

                       out h pty,

                       out s pty_path);

      OpenMachineShell(in  s name,

                       in  s user,

                       in  s path,

                       in  as args,

                       in  as environment,

                       out h pty,

                       out s pty_path);

      BindMountMachine(in  s name,

                       in  s source,

                       in  s destination,

                       in  b read_only,

                       in  b mkdir);

      CopyFromMachine(in  s name,

                      in  s source,

                      in  s destination);

      CopyToMachine(in  s name,

                    in  s source,

                    in  s destination);

      OpenMachineRootDirectory(in  s name,

                               out h fd);

      GetMachineUIDShift(in  s name,

                         out u shift);

      RemoveImage(in  s name);

      RenameImage(in  s name,

                  in  s new_name);

      CloneImage(in  s name,

                 in  s new_name,

                 in  b read_only);

      MarkImageReadOnly(in  s name,

                        in  b read_only);

      GetImageHostname(in  s name,

                       out s hostname);

      GetImageMachineID(in  s name,

                        out ay id);

      GetImageMachineInfo(in  s name,

                          out a{ss} machine_info);

      GetImageOSRelease(in  s name,

                        out a{ss} os_release);

      SetPoolLimit(in  t size);

      SetImageLimit(in  s name,

                    in  t size);

      CleanPool(in  s mode,

                out a(st) images);

      MapFromMachineUser(in  s name,

                         in  u uid_inner,

                         out u uid_outer);

      MapToMachineUser(in  u uid_outer,

                       out s machine_name,

                       out o machine_path,

                       out u uid_inner);

      MapFromMachineGroup(in  s name,

                          in  u gid_inner,

                          out u gid_outer);

      MapToMachineGroup(in  u gid_outer,

                        out s machine_name,

                        out o machine_path,

                        out u gid_inner);

    signals:

      MachineNew(s machine,

                 o path);

      MachineRemoved(s machine,

                     o path);

    properties:

      @org.freedesktop.DBus.Property.EmitsChangedSignal("false")

      readonly s PoolPath = '...';

      @org.freedesktop.DBus.Property.EmitsChangedSignal("false")

      readonly t PoolUsage = ...;

      @org.freedesktop.DBus.Property.EmitsChangedSignal("false")

      readonly t PoolLimit = ...;

  };

  interface org.freedesktop.DBus.Peer { ... };

  interface org.freedesktop.DBus.Introspectable { ... };

  interface org.freedesktop.DBus.Properties { ... };
};

```

### Methods
GetMachine() may be used to get the machine object path for the machine with the specified name. Similarly, GetMachineByPID() gets the machine object the specified PID belongs to if there is any.

GetImage() may be used to get the image object path of the image with the specified name.

ListMachines() returns an array of all currently registered machines. The structures in the array consist of the following fields: machine name, machine class, an identifier for the service that registered the machine and the machine object path.

ListImages() returns an array of all currently known images. The structures in the array consist of the following fields: image name, type, read-only flag, creation time, modification time, current disk space, and image object path.

CreateMachine() may be used to register a new virtual machine or container with systemd-machined, creating a scope unit for it. It accepts the following arguments: a machine name chosen by the registrar, an optional UUID as a 32 byte array, a string that identifies the service that registers the machine, a class string, the PID of the leader process of the machine, an optional root directory of the container, and an array of additional properties to use for the scope registration. The virtual machine name must be suitable as a hostname, and hence should follow the usual DNS hostname rules, as well as the Linux hostname restrictions. Specifically, only 7 bit ASCII is permitted, a maximum length of 64 characters is enforced, only characters from the set "a-zA-Z0-9-_." are allowed, the name may not begin with a dot, and it may not contain two dots immediately following each other. Container and VM managers should ideally use the hostname used internally in the machine for this parameter. This recommendation is made in order to make the machine name naturally resolvable using nss-mymachines(8). If a container manager needs to embed characters outside of the indicated range, escaping is required, possibly using "_" as the escape character. Another (somewhat natural) option would be to utilize Internet IDNA encoding. The UUID is passed as a 32 byte array or, if no suitable UUID is available, an empty array (zero length) or zeroed out array shall be passed. The UUID should identify the virtual machine/container uniquely and should ideally be the same UUID that /etc/machine-id in the VM/container is initialized from. The service string can be free-form, but it is recommended to pass a short lowercase identifier like "systemd-nspawn", "libvirt-lxc" or similar. The class string should be either "container" or "vm" indicating whether the machine to register is of the respective class. The leader PID should be the host PID of the init process of the container or the encapsulating process of the VM. If the root directory of the container is known and available in the host's hierarchy, it should be passed. Otherwise, pass the empty string instead. Finally, the scope properties are passed as array in the same way as to PID1's StartTransientUnit() method. Calling this method will internally register a transient scope unit for the calling client (utilizing the passed scope_properties) and move the leader PID into it. The method returns an object path for the registered machine object that implements the org.freedesktop.machine1.Machine interface (see below). Also see the New Control Group Interfaces[1] for details about scope units and how to alter resource control settings on the created machine at runtime.

RegisterMachine() is similar to CreateMachine(). However, it only registers a machine and does not create a scope unit for it. Instead, the caller's unit is registered. We recommend to only use this method for container or VM managers that are run multiple times, one instance for each container/VM they manage, and are invoked as system services.

CreateMachineWithNetwork() and RegisterMachineWithNetwork() are similar to CreateMachine() and RegisterMachine() but take an extra argument: an array of network interface indices that point towards the virtual machine or container. The interface indices should reference one or more network interfaces on the host that can be used to communicate with the guest. Commonly, the passed interface index refers to the host side of a "veth" link (in case of containers), a "tun"/"tap" link (in case of VMs), or the host side of a bridge interface that bridges access to the VM/container interfaces. Specifying this information is useful to enable support for link-local IPv6 communication to the machines since the scope field of sockaddr_in6 can be initialized by the specified ifindex. nss-mymachines(8) makes use of this information.

KillMachine() sends a UNIX signal to the machine's processes. As its arguments, it takes a machine name (as originally passed to CreateMachine() or returned by ListMachines()), an identifier that specifies what precisely to send the signal to (either "leader" or "all"), and a numeric UNIX signal integer.

TerminateMachine() terminates a virtual machine, killing its processes. It takes a machine name as its only argument.

GetMachineAddresses() retrieves the IP addresses of a container. This method returns an array of pairs consisting of an address family specifier (AF_INET or AF_INET6) and a byte array containing the addresses. This is only supported for containers that make use of network namespacing.

GetMachineOSRelease() retrieves the OS release information of a container. This method returns an array of key value pairs read from the os-release(5) file in the container and is useful to identify the operating system used in a container.

OpenMachinePTY() allocates a pseudo TTY in the container and returns a file descriptor and its path. This is equivalent to transitioning into the container and invoking posix_openpt(3).

OpenMachineLogin() allocates a pseudo TTY in the container and ensures that a getty login prompt of the container is running on the other end. It returns the file descriptor of the PTY and the PTY path. This is useful for acquiring a pty with a login prompt from the container.

OpenMachineShell() allocates a pseudo TTY in the container, as the specified user, and invokes the executable at the specified path with a list of arguments (starting from argv[0]) and an environment block. It then returns the file descriptor of the PTY and the PTY path.

BindMountMachine() bind mounts a file or directory from the host into the container. Its arguments consist of a machine name, the source directory on the host, the destination directory in the container, and two booleans, one indicating whether the bind mount shall be read-only, the other indicating whether the destination mount point shall be created first, if it is missing.

CopyFromMachine() copies files or directories from a container into the host. It takes a container name, a source directory in the container and a destination directory on the host as arguments. CopyToMachine() does the opposite and copies files from a source directory on the host into a destination directory in the container.

RemoveImage() removes the image with the specified name.

RenameImage() renames the specified image.

CloneImage() clones the specified image under a new name. It also takes a boolean argument indicating whether the resulting image shall be read-only or not.

MarkImageReadOnly() toggles the read-only flag of an image.

SetPoolLimit() sets an overall quota limit on the pool of images.

SetImageLimit() sets a per-image quota limit.

MapFromMachineUser(), MapToMachineUser(), MapFromMachineGroup(), and MapToMachineGroup() may be used to map UIDs/GIDs from the host user namespace to a container user namespace or vice versa.

### Signals
MachineNew and MachineRemoved are sent whenever a new machine is registered or removed. These signals carry the machine name and the object path to the corresponding org.freedesktop.machine1.Machine interface (see below).

### Properties
PoolPath specifies the file system path where images are written to.

PoolUsage specifies the current usage size of the image pool in bytes.

PoolLimit specifies the size limit of the image pool in bytes.

## MACHINE OBJECTS

```
node /org/freedesktop/machine1/machine/rawhide {

  interface org.freedesktop.machine1.Machine {

    methods:

      Terminate();

      Kill(in  s who,

           in  i signal);

      GetAddresses(out a(iay) addresses);

      GetOSRelease(out a{ss} fields);

      GetUIDShift(out u shift);

      OpenPTY(out h pty,

              out s pty_path);

      OpenLogin(out h pty,

                out s pty_path);

      OpenShell(in  s user,

                in  s path,

                in  as args,

                in  as environment,

                out h pty,

                out s pty_path);

      BindMount(in  s source,

                in  s destination,

                in  b read_only,

                in  b mkdir);

      CopyFrom(in  s source,

               in  s destination);

      CopyTo(in  s source,

             in  s destination);

      OpenRootDirectory(out h fd);

    properties:

      @org.freedesktop.DBus.Property.EmitsChangedSignal("const")

      readonly s Name = '...';

      @org.freedesktop.DBus.Property.EmitsChangedSignal("const")

      readonly ay Id = [...];

      @org.freedesktop.DBus.Property.EmitsChangedSignal("const")

      readonly t Timestamp = ...;

      @org.freedesktop.DBus.Property.EmitsChangedSignal("const")

      readonly t TimestampMonotonic = ...;

      @org.freedesktop.DBus.Property.EmitsChangedSignal("const")

      readonly s Service = '...';

      @org.freedesktop.DBus.Property.EmitsChangedSignal("const")

      readonly s Unit = '...';

      @org.freedesktop.DBus.Property.EmitsChangedSignal("const")

      readonly u Leader = ...;

      @org.freedesktop.DBus.Property.EmitsChangedSignal("const")

      readonly s Class = '...';

      @org.freedesktop.DBus.Property.EmitsChangedSignal("const")

      readonly s RootDirectory = '...';

      @org.freedesktop.DBus.Property.EmitsChangedSignal("const")

      readonly ai NetworkInterfaces = [...];

      @org.freedesktop.DBus.Property.EmitsChangedSignal("false")

      readonly s State = '...';

  };

  interface org.freedesktop.DBus.Peer { ... };

  interface org.freedesktop.DBus.Introspectable { ... };

  interface org.freedesktop.DBus.Properties { ... };
};

```

### Methods
Terminate() and Kill() terminate/kill the machine. These methods take the same arguments as TerminateMachine() and KillMachine() on the Manager interface, respectively.

GetAddresses() and GetOSRelease() get the IP address and OS release information from the machine. These methods take the same arguments as GetMachineAddresses() and GetMachineOSRelease() of the Manager interface, respectively.

### Properties
Name is the machine name as it was passed in during registration with CreateMachine() on the manager object.

Id is the machine UUID.

Timestamp and TimestampMonotonic are the realtime and monotonic timestamps when the virtual machines where created in microseconds since the epoch.

Service contains a short string identifying the registering service as passed in during registration of the machine.

Unit is the systemd scope or service unit name for the machine.

Leader is the PID of the leader process of the machine.

Class is the class of the machine and is either the string "vm" (for real VMs based on virtualized hardware) or "container" (for light-weight userspace virtualization sharing the same kernel as the host).

RootDirectory is the root directory of the container if it is known and applicable or the empty string.

NetworkInterfaces contains an array of network interface indices that point towards the container, the VM or the host. For details about this information see the description of CreateMachineWithNetwork() above.

State is the state of the machine and is one of "opening", "running", or "closing". Note that the state machine is not considered part of the API and states might be removed or added without this being considered API breakage.

## EXAMPLES
Example 1. Introspect org.freedesktop.machine1.Manager on the bus

```
$ gdbus introspect --system \

  --dest org.freedesktop.machine1 \

  --object-path /org/freedesktop/machine1

```

Example 2. Introspect org.freedesktop.machine1.Machine on the bus

```
$ gdbus introspect --system \

  --dest org.freedesktop.machine1 \

  --object-path /org/freedesktop/machine1/machine/rawhide

```

## VERSIONING
These D-Bus interfaces follow the usual interface versioning guidelines[2].

## NOTES
1.

New Control Group Interfaces

https://www.freedesktop.org/wiki/Software/systemd/ControlGroupInterface/

2.

the usual interface versioning guidelines

http://0pointer.de/blog/projects/versioning-dbus.html